This chemistry blog is aimed mainly at senior high school students or first year university students. It covers general chemistry topics required in Colleges and Universities. However, chemistry topics of general interest are going to be included.

Step 3 & 4: One double bond must therefore be
placed through the 3 S-O bonds. Therefore, the Lewis structures for SO3
are as follows:

Figure 1: Lewis structures for SO3. In
this case the sulfur atom, using valency shell n =3 is not restricted to an
octet, and additional double bonds may be generated from the oxygen lone
pairs to equalize the charge. Resonance structure 4 is the most probable
one since the there is no charge separation.